Impact of in-car traffic information

In-car traffic information is maturing. Navigation systems that use real-time traffic data to provide information and guidance to the driver are becoming more and more common. The number of vehicles with such a system on board is still relatively small, but increasing steadily. It is not yet clear how the traffic system will change when the penetration level will increase substantially. Is there still a need for providing traffic information via DRIPs? What will the impact of these systems be on Dynamic Traffic Management in general?